Double beam scales are ideal for use in the classroom, laboratory, or pharmacy, where an accurate and reliable scale is required. The sleek and durable design of double beam scales also makes them great for use in manufacturing, mining, and other industries where scales are continually exposed to rugged use.
Double beam scales work in the same way a traditional triple beam scale does, only using two beams. In general, there are two common types of double beam scales that are often accurate to one tenth of a gram. Double beam tabletop scales, which are often found in classrooms and laboratories, and the more popular medical scale, which is often found in a doctor’s office. There are also application-specific double beam scales such as gem scales, which provide higher accuracy and offer different weighing modes. Although these double beam scales vary in appearance, their components and the way to operate them are similar.
The parts of a double beam scale include one or two weighing pans, two rider beams, two riders or sliding masses, and a pointer. The weighing pan is where you place the objects that you want to weigh and is connected to the rider beams. The rider beams are horizontal bars, which the riders are attached to and may include notches or slots for the riders to rest in. One rider beam is marked with progressively increasing larger weight increments and includes a heavier rider, while the other rider beam is marked with more precise increments of measurement and includes a lighter rider. By adjusting the position of the riders on the rider beams, the pointer will either move up or down in comparison to the center mark. The idea is to get the pointer to line up directly with the center mark, indicating that the measurement is accurate.
Before using a double beam scale, its good practice to make sure that the scale is properly adjusted by making sure the rider beam is parallel to the floor and that the pointer is at zero with nothing on the scale. Now you’re ready to place your object on the weighing pan, or have the person to be weighed step on the weighing pan. You’ll see the point move up until it reaches the stopper and cannot move any further. Move the larger rider, on the rider bar with larger increments, to the right until the pointer falls all the way down and then move it back one increment so that the point is just above the center mark. Now its time to adjust the smaller rider slowly across its rider bar until the pointer is pointing directly at the center mark. To determine your objects total weight, simply add the two weight increments together.